Merge

7117303: VM uses non-monotonic time source and complains that it is non-monotonic Summary: Replaces calls to os::javaTimeMillis(), which does not (and cannot) guarantee monotonicity, in GC code to an equivalent expression that uses os::javaTimeNanos(). os::javaTimeNanos is guaranteed monotonically non-decreasing if the underlying platform provides a monotonic time source. Changes in OS files are to make use of the newly defined constants in globalDefinitions.hpp. Reviewed-by: dholmes, ysr

7120038: G1: ParallelGCThreads==0 is broken Summary: Running G1 with ParallelGCThreads==0 results in various crashes and asserts. Most of these are caused by unguarded references to the worker threads array or an incorrect number of active workers. Reviewed-by: jmasa, tonyp

7113012: G1: rename not-fully-young GCs as "mixed" Summary: Renamed partially-young GCs as mixed and fully-young GCs as young. Change all external output that includes those terms (GC log and GC ergo log) as well as any comments, fields, methods, etc. The changeset also includes very minor code tidying up (added some curly brackets). Reviewed-by: johnc, brutisso

7119908: G1: Cache CSet start region for each worker for subsequent reuse Summary: Cache workers' calculated starting heap region, used for parallel iteration over the collcection set, for subsequent reuse. Reviewed-by: tonyp, brutisso

7121373: Clean up CollectedHeap::is_in Summary: Fixed G1CollectedHeap::is_in, added tests, cleaned up comments and made Space::is_in pure virtual. Reviewed-by: brutisso, tonyp, jcoomes